Design, synthesis, and in silico studies of benzimidazoles of thymol as potent antiplasmodial and antimicrobial agents

This study presents an efficient one pot two steps synthesis of a new series of naturally occurring phenolic monoterpenoid based (thymol) benzimidazole derivatives (3a-i) by green approach. The structures of all newly synthesized benzimidazoles are confirmed by 1H NMR, 13C NMR, Mass, and FT-IR spectroscopic analyses. The synthesized compounds were examined for their in vitro antimalarial, antioxidant and antimicrobial activities. Antimalarial activity tested against P. falciparum strain, the IC50 values of all the tested compounds are in the range from 0.32 to 1.54 mu g/mL. Biological screening revealed that some synthesized benzimidazoles possess very interesting biological activities. Molecular docking simulation against the potent inhibitors Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) enzyme indicated that potent compounds 3a, 3f, and 3 g have significant binding energy (-7.9 to -9.7 Kcal/mol). The in silico ADME properties estimated for the synthesized compounds indicated them as very good oral bioavailability drugs.